阅读下面短文，从A、B、C、D四个选项中选出最佳选项。

Where does the wind come from? What makes the wind move(移动) all the time? Scientists tell us that it is the sun. That makes air move, and makes it blow(吹). When the sun shines on the earth, it makes the earth hot. Then the earth makes the air hot. When the air becomes hotter, it also becomes lighter(更轻). The light air goes up. Cool air comes into take the place of（代替） the hot air. The hot light air goes up higher and higher until it becomes cool. Then it comes down again, and then the earth makes it hot again, and it has to go up. When the air move, it has wind.

用如图所示的刻度尺测量物体的长度，该刻度尺的分度值是　 ____，读数时，视线要与被测物的边缘 ____，图中被测物体的长度为　 ____cm．

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（1）如图1甲、乙是两种声音的波形图，从图形可知： ____是乐音的波形图， ____是噪声的波形图；

（2）如图2所示，小华将一只正在发声的音叉触及面颊有震感，这个实验是用来探究　 ____　

A．声音产生的原因

B．决定音调的因素

C．声音能否在空气中传播

D．声音传播是否需要时间。